WASHINGTON, Feb 28 (Reuters) - A day before sweeping budgetcuts begin, the White House and Republicans blamed each other onThursday for failure to prevent a fiscal crisis which theInternational Monetary Fund warned could slow the U.S. and worldeconomies.

While Democrats and Republicans disagree about how severethe damage will be to public services like air traffic controland law enforcement, the IMF said the economic recovery wouldlikely be harmed by the automatic spending cuts known as"sequestration."

"We will see what happens on Friday, but everybody isassuming that sequestration is going to take effect," IMFspokesman William Murray said. "What it means is that we aregoing to have to reevaluate our growth forecasts for the UnitedStates and other forecasts," he added.

The full brunt of the automatic cuts will be borne overseven months and Congress can stop them at any time if the twoparties agree on how to do so.

That makes it difficult to say how the belt tightening willhit ordinary Americans. President Barack Obama's administrationis warning that Navy ships could lie idle and children will loseout on vaccinations if the cuts are not halted.

The IMF would likely shave at least 0.5 percentage point offits 2013 U.S. economic growth forecast of 2 percent ifsequestration is fully implemented.

Put into law in 2011 as part of a bipartisan solution to anearlier fiscal emergency, sequestration is unloved by bothparties because of the economic pain it will cause.

Few believed two years ago that the cuts would come intoforce but, unable to agree on any other way to reduce the budgetdeficit, political leaders are pointing fingers at each othernow that the spending reductions appear inevitable.

"It is the president's sequester. It was his team thatinsisted upon it," Republican House of Representatives SpeakerJohn Boehner said.

White House spokesman Jay Carney said Republicans' refusalto compromise by agreeing to close tax loopholes on the wealthywas one reason why the cuts might be unavoidable.

"Compromise represents willingness to accept policies thataren't 100 percent of what you want. The president has done thatagain and again. Unfortunately, Republicans seem to be unwillingto do that when it comes to the sequester, so the sequester maytake place," he told reporters.

He said both sides had agreed to the cuts, half of whichwill come from the defense budget and half from non-defensedomestic programs.

WOODWARD FIGHT

"It was designed as policy that would never come intoeffect. Because it was so onerous for both sides, it wouldcompel Congress to reach a compromise," Carney said.

Debate over the run-up to sequestration is at the root of adispute between the White House and famed Washington journalistBob Woodward, who is known for his groundbreaking reporting ofthe Watergate scandal in the 1970s.

Woodward this week accused one of Obama's senior economicofficials, Gene Sperling, of threatening him in an email forreporting that the White House was "moving the goal posts" inthe budget talks.

Obama will meet congressional leaders in the White House onFriday for last-minute budget talks but hopes were low of adeal.

Recent polls show that, despite efforts in Washington todisown any responsibility for the cuts, many Americans welcomelower government spending.

A NBC/Wall Street Journal poll released Wednesday showed 53percent of Americans preferred the planned cuts or even greaterspending cuts than no cuts at all.

Neil Whitman, 62, who runs Dunhill Staffing, an employmentcompany based in Mt. Pleasant, South Carolina, said Washingtonhad just authorized spending of around $60 billion in relief forSuperstorm Sandy.

"We spent that in a blink of an eye," he said. "You take $85billion from somewhere else. So what?"

Whitman said he doubted the horror stories emerging fromWashington of public services decimated by sequestration.

"To me, it's political," he said. "I think we need tocontrol spending, but we need to stop telling the Americanpeople, 'I don't know if we can guarantee your safety on theairplanes.'"

The Senate voted on Thursday against plans by both Democratsand Republicans to replace the cuts.

The Republican plan would have let the cuts go into effecton Friday, but required Obama to submit an alternative $85billion spending reduction plan to Congress by March 15, thusallowing more flexibility on how the cuts would be carried out.

The Democratic proposal would have replaced theacross-the-board cuts mainly with tax increases on the richcoupled with spending cuts. Some of those would be achieved byeliminating crop subsidies for large agricultural companies.More savings would be through minor defense cuts in later years.